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Allocating and Formatting Files › Types of Files

Types of Files

Available Options

CA IDMS/DB can access data stored in the following types of files:

File Type

Access Method

File Structure

Direct access

EXCP (z/OS, z/VSE)

A file block corresponds to a database page

Physical sequential

 

EXCP (z/OS)

SAM (z/VSE)

A file block corresponds to a database page

CMS format minidisk

DASD block I/O (z/VM)

A file block corresponds to a database page

VSAM database

VSAM (z/OS, z/VSE)

An ESDS VSAM file in which each Control Interval contains a single database page plus 8 bytes of control information used by VSAM

Native VSAM

VSAM (z/OS, z/VSE)

An ESDS, KSDS, or RRDS VSAM file or PATH in which each VSAM record corresponds to an IDMS record

Specifying the File Type in the FILE Statement

When you define a file using a physical DDL FILE statement, you specify the file's type using these parameters:

FILE Statement Parameter

Corresponding File Type

NONVSAM or BDAM

Direct access (z/OS, z/VSE)

Physical sequential (z/OS)

CMS format minidisk (z/VM)

VSAM

VSAM database (z/OS, z/VSE)

 

ESDS

KSDS

RRDS

PATH

Native VSAM (z/OS, z/VSE)